Fluid depolarized battery with improved automatic valve

ABSTRACT

This invention contemplates using semiconductor microactuators as small valves in combination with electric appliances powered by fluid depolarized electrochemical batteries, especially zinc-air cells, or in combination with fluid depolarized electrochemical batteries themselves, all to regulate fluid flow into the batteries. The purpose is to prevent degradation of the batteries when idle, yet permit fluid flow when operating and only when operating. The valves are proposed to be modified to use them as movement devices and valves, using the traditional moving part of the semiconduictor microactuator to move a slide. To increase the area available for fluid flow, the invention proposes to use grids of aperatures for structural integrity, which when the grids are aligned, allows for fluid flow, and when &#34;unaligned&#34; in the normally closed position, block fluid flow. Pressure relief characteristics, corrosion protection, control circuitry, circulation means, and other advantages and methods are also claimed.

This application is a continuation-in-part of Ser. No. 07/886,513, filedMay 20, 1992, now U.S. Pat. No. 5,304,431 and a continuation-in-part ofSer. No. 886,725 filed May 21, 1992.

FIELD OF THE INVENTION

This invention relates to an electrical appliance especially adapted toan improved fluid depolarized electrochemical battery comprising atleast one cell, particularly those consuming oxygen from the air. Anefficient semiconductor microactuator (a valve-on-a-chip) is placed onthe case of an electrical appliance or within a sealed battery (abattery including at least one cell) so that the semiconductormicroactuator is the sole means of entry of fluid depolarizer, mostoften air, to the battery, permitting the battery to operate when thebattery is supplying electrical current to a load. The invention alsoencompasses micromachining a valve mechanism. The inventionexcludes-fluid depolarizer and impurities when the battery is notsupplying electrical current to an electrical load to prevent thebattery from discharging and losing power capacity while not in use. Thesemiconductor microactuator on the battery will break down in such a waywhen the battery "leaks" to minimize the damage to the device thebattery is operating. The semiconductor microactuator acts as a pressurerelief valve. The semiconductor microactuator may also be designed toact more optimally as a safety pressure valve or as a fuse. Theelectrical appliance and battery is rechargeable and this inventioncovers the combination with a recharger and with a control device tomaximize the charge.

BACKGROUND OF THE INVENTION

Fluid depolarized cells exist in many types and varieties. The mostcommon in commercial use today are metal-air depolarized cells to whichthis invention relates are described in McArthur et al., U.S. Pat. No.4,547,438, Oct. 15, 1985, Zupanic, U.S. Pat. No. 4,529,673, Jul. 16,1985, Mathews et al., U.S. Pat. No. 4,177,327, and literature cited inthose patents.

The principal advantage of zinc-air cells is that higher energy density,i.e., watts per unit of mass, can be achieved using oxygen in the air,or other Gas, as a "fluid" cathode material. This is, instead of, forinstance, the solid material found in a typical home flashlight battery.A cell of a given standard size can contain much more anode andelectrolyte volume because the oxygen reactant is "stored" outside inthe atmosphere. This is useful in small devices such as hearing aids,and also useful in larger cells, such as flashlight "D" or "C" cells, orin the largest of batteries such as in an electric car where much poweris needed, but space used takes away from space for other uses.Similarly, a cellular or portable phone is a good use. The sameprinciple applies for a cell in which a liquid, including seawater, is areactant, particularly for an underwater application.

The General design and technical aspects of the cell, in a typical cell(or combination of cells, referred to as a battery) are well-known inthe literature, are more specifically described in pending Application07/886,513, now U.S. Pat. No. 5,304,431, and are described in Schumm,Jr., "Batteries," Encyclopedia of Physical Science and Technology, vol.2, p. 387, 390, 396-97 (Academic Press, Inc. 1987) The metals which canbe used include, for example, lead, calcium, beryllium, and lithium andalloys and mixtures of those elements. The use of the word "air" isemployed for convenience to mean an oxygen source, which source couldthus be other gas mixtures including oxygen.

In a single gas depolarized electrochemical cell, for instance one ofthe Gould type, Cretzmeyer et al., U.S. Pat. No. 4,189,526, the airenters through vent holes in the outside container of the cell through acoating of polytetrafluoroethylene (often sold as "Teflon", Trademark ofDupont Co.) layer.

When such a cell is not operating, the reactant fluid, oxygen in theair, as well as other impurities, must be excluded. Previously, nocombination of a valve and battery existed where the parasitic use ofpower by the valve did not substantially diminish the life or the powerof the cell or consume too much space or structure.

Excluding fluids and depolarizing gas prevents the cell from degradingthrough several processes of corrosion, moisture change and impurityentry which: a) shorten the "shelf" or storage life of the cell when itis not in use, and b) necessitate more frequent changes of the cell inan electrically powered device. Since a common use for this type of cellis for a hearing aid, it is commercially useful not to have to changethe battery so frequently.

Another common use for the cell is in a buoy at sea; exclusion of thehumid, salty sea air when the cell is not operating and reduction of thefrequency in changing the cell, or cells in a battery, save much laborand money. The control of the passage of water vapor by the valveprevents the cell from swelling or otherwise being damaged, and preventsdehydration of the cell while not operating. Also, carbon dioxide, whichdegrades the performance of the cell, is precluded from entering thecell when the cell is not operating.

Previous engineering designs used a variety of means to attempt toovercome these problems. Several inventions used a mechanism physicallyoperated by the user where the valve or vent cover is attached to theswitch turning a device "on" so that when the switch moves, the covermoves. Derksen, U.S. Pat. No. 2,468,430 dated Apr. 3, 1949, and H. R.Espig and D. F. Porter, Power Sources 4: Research and Development inNon-Mechanical Electrical Power Sources, Proceedings of the 8thInternational Symposium held at Brighton, September, 1972 (Oriel Press)at p. 342. The physical presence of the operator is required, as well asa device designed with a switch compatible with the battery system.

Another obvious and long-known approach is a solenoid or electromagneticmeans to move a valve or cover as the device is turned on or off, which,consumes a substantial amount of the power of the cell or takes upsubstantial space.

A more primitive approach which is effective before the cell is operatedis to place a sealing tab or plug on the cell (like a pull-tab on a sodacan) to be removed when the cell is put in service, admitting oxygen tothe assembly. The sealing tab or plug in combination with an airtightassembly at least prevents the deactivation of the zinc from externalsources before use (while on the "shelf"), but once activated byremoving the tab, small cells must be used completely within 1 to 3months, or the cell will have self-discharged or dried out with nouseful power remaining. If the cell is operated continuously, this"once-opened/always-opened" characteristic makes little difference, butsince most electrical devices are at least occasionally turned off for aperiod of time, a recloseable valve is important to protect the cellfrom degradation during that time.

The art of Mathews, U.S. Pat. No. 4,177,327, Dec. 4, 1979, previouslymentioned, contemplates using a vent cover, in the form of a plug or aflap, in conjunction with an electrical heating element. The bimetalelement in the '327 patent is referenced as 1.625 inches (4.1 cm) long.The heating element was referenced to cover 0.75 inches (1.9centimeters). The embodiment in the Mathews patent contemplated that thebimetal element would move to produce a clearance of 0.30 inches (0.75centimeters). The moving portion of the vent cover assembly in theMathews invention is parallel or roughly parallel to the flow of airinto the cell. That position requires either 1) a significant loss ofdimension in the length of the cell, if the cell is a cylinder, 2) areduction in the available space of a cylindrical cell by creation of acavity in the side of the cell, or 3) a reduction in the height of thecell to accommodate the vent cover and heating apparatus. By comparison,a typical hearing aid battery is 1.16 centimeters ("cm.") in diameterand 0.42 cm. to 0.54 cm. thick, a typical size "C" flashlight battery is2.6 cm. in diameter and 5 cm. high; a typical size "D" flashlightbattery is 3.4 cm. in diameter and 6.0 centimeters high (Thevalve-on-a-chip is 0.4 cm.×0.4 cm.×0.1 cm. in total size).

The present invention uses significantly less space and is thereforesuited to a single small cell configuration, or small electricalappliance configuration and avoids the loss in energy density eitherbecause of lower power drain or less space consumed or both.

In addition, the present invention is intended to be used, which was notdisclosed in the prior art, to act as a pressure relief valve becausethe cover is to the exterior of the inlet to the interior of theappliance or the cell or battery so that a plug or flap is not "trapped"against the outside container of the cell or battery. Further, anotherobjective not disclosed or intended in the prior art, is to usecorrosive fluid, if the semiconductor microactuator is mounted on thebattery, or the inlet to the battery is juxtaposed to the valve mountedon the electrical appliance so that when the battery "leaks", theleaking fluid clogs or distorts the semiconductor microactuator andcauses the cell to cease to function generally by oxygen deprivation,although it may also occur by damaging the heating element which opensthe semiconductor microactuator. This more reliably causes the batteryto cease to operate when it is leaking than did the devices in the priorart.

In all, the difficulty has been to produce a combination that preservesthe energy density of the cell or electrical appliance and at the sametime provides a cell that can be "dropped into" a device and functionautomatically to preclude fluid and impurity entry while the cell anddevice are not operating. In addition, a pressure relief characteristicand "shutdown" of the cell on malfunction or "leakage" would be helpful,but all of these functions together have not been achieved in the priorart.

Previously, limited efforts had been made to have certain types ofvalves on liquid electrolyte electrochemical cells as well. The priorart of Cheron, U.S. Pat. No. 4,039,728, is related to a valve whichconsumed substantial power which was the means, in combination with afuel cell, i.e., a special type of fluid depolarized electrochemicalcell, to control the circulation of liquid electrolyte in the cell,which valve was actuated based on a parameter which is a function of thecirculation of the electrolyte in the cell.

This invention overcomes the power and space requirements by using thenew combination of an automatic valve of different materials and size,preferably a small electronic semiconductor microactuator, a"valve-on-a-chip", after the art of J. H. Jerman, U.S. Pat. No.5,069,419, Dec. 3, 1991, J. H. Jerman, U.S. Pat. No. 5,271,597, Dec. 21,1993, W. America, U.S. Pat. No. 4,969,938, Nov. 13, 1990, or a"Fluistor" semiconductor microactuator, described in Instruments andApparatus News [IAN], October, 1993, p. 47, and Electronic Design, Nov.1, 1993 p. 34, (those valves and like valves, including those referencedin those patents, referred to as a "semiconductor actuator valve,""semiconductor microactuator valve", "semiconductor microactuator valvemeans," or "valve-on-a-chip") in conjunction with a sealed fluiddepolarized electrochemical cell, especially a zinc-air cell, or mountedon an electrical appliance in such conjunction. The sole means of entryof depolarizing fluid is through the valve-on-a-chip. The combinationproduces a new and commercially useful invention by employing recentadvances in semiconductor and micromachining technology that were notpreviously commercially available or invented. The inventioncontemplates the use of at least two layers, one of metal and one ofsemiconductor material, juxtaposed to each other. The invention furthercontemplates a modified valve design, using a grid structure inside thevalve, or using the valve to power a slide or flex a grid, particularlyin combination with the liquid propelled thermally responsivesemiconductor microactuators.

To achieve a more cost-effective solution in certain electricalappliances, if the valve is mounted on the sealed case of the appliance,or on a sealed compartment containing the cell, and is connected inseries with a switch, the valve may be "purchased once" with theelectrical appliance, and an existing cell without a semiconductormicroactuator used. The slide or grid mechanism described herein hasspecial advantages for higher fluid flow applications, particularly forliquids which have lower aperture diffusion rates for a given volume.

The way that the valve and cell combination works is that when theelectrical device the cell is powering is "turned on", the consequentclosing of the operating circuit causes the valve to open, admittinggas, normally air, to the cell. When the circuit is opened, meaning theelectrical device the cell is powering is "turned off", the valvecloses, precluding entry or exit of fluids or other impurities. Thevalve does not close as quickly as it opens, but this time is notsignificant compared to the many hours of time when exposure to the airwould be typically closed off, and has the additional advantage ofpreventing "chatter", or unnecessary vibration, in certain applications.

There is sufficient residual oxygen or oxide compounds in the cell sothat the cell will deliver sufficient power to start up and operate thevalve-on-a-chip. This can be enhanced by the use of manganese dioxide orother catalytic agents in the cell. Such a cell has a higher startingpower before oxygen fully penetrates the cathode pore structure. In anycase a potential of generally over one volt exists between the cellelectrodes. When the circuit containing the apparatus to be operated isclosed, this invention causes electrons to flow from the zinc anode(s)through the electrical circuit and the valve to the cathode(s) of thecell or cells. Tuck, Modern Battery Technology, Ellis Horwood Series inApplied Science and Industrial Technology at generally p. 126-188(London, NY 1991).

This valve has the additional advantage that it is conducive to apressure relief characteristic which continues to be usable as a ventclosure after relief of the pressure.

BRIEF SUMMARY OF THE INVENTION

The primary object of this invention is to combine a new type of valvewith an electrical appliance or a fluid depolarized battery or cell toextend the life of the battery while preserving the energy density ofthe battery.

The preferred embodiment uses a micromachined electrically activated,thermally responsive semiconductor microactuator. Impurities anddepolarizing gas are excluded from the electrical appliance or batterywhile it is off, and when a circuit containing the battery is activated,the semiconductor microactuator opens and the battery operates. Theprimary characteristic of the combination that achieves these objectivesis the self-contained, normally closed aspect with the activationinternal to the valve and adjacent to the valve opening. The valve issolely activated internally by the closing of an electrical circuitcontaining the valve and is not physically actuated by any meansexternal to the valve such as an external solenoid or magnet, externalmechanical or electromechanical device, physical connection with aswitch or an external heating element unless mounted on the electricalappliance itself, in which case the operating switch for the applianceactivates the valve and appliance simultaneously.

The dual objectives of a valve cooperating with a battery or cell torelieve pressure, and also ceasing to function, if mounted on thebattery or cell, in the event of internal leakage from the interior ofthe battery or cell are achieved by this invention at the same timethese power and size advantages are being realized.

By adding a resistance in parallel with the valve to change the apparentresistance of the invention, and in particular the combined resistanceof the shunt resistance and the valve, the invention can be optimized tothe operational voltage or amperage of the electrical load powered bythe apparatus. For instance, in a typical flashlight cell, the desiredvoltage is less than the standard electric potential output of azinc-air cell, and the internal resistance of the valve mechanism and ashunt resistance can reduce the voltage to a desired level. In keepingwith the miniature size, the resistance may be a thin film resistancedeposited on the semiconductor microactuator depending on theoperational characteristics desired.

The invention is directed to a power supply in an electrical appliancecomposed of single cells and in batteries of cells. The invention isfirst directed to a the combination in a single cell with anelectrothermally responsive valve and a resistance in parallel with sucha valve that cooperate together to achieve certain energy density andperformance characteristics. The invention is also directed to thecombination of a battery or cell and the process of placing anelectrothermally responsive valve in combination with the battery orcell. The invention is also directed to the combination of a particulartype of electrothermally responsive valve: a semiconductor microactuatorin a battery or cell. The invention is also directed to the method ofregulating fluid flow in a battery. The invention is also directed tomounting the electrothermally responsive valve on an appliance so thatstandard zinc-air cells are protected and the valve cost is only paidonce in connection with the manufacture of the electrical appliancestructure and not for each cell or battery.

It is an object and advantage of this invention that the valve can alsobe designed to release pressure at specified levels by varying thediaphragm characteristics.

By achieving such objectives, a device particularly suited for smallapplication such as hearing aid cells, and cells the size of D, or Cflashlight batteries or other common sizes is realized. By not needingto change the shape of the cell because of the small valve, the cell maybe "dropped-in" to existing applications without need for modificationof existing electrical devices which the invention will power.Alternatively, the appliance may be modified, and standard cells used.

The invention also may be modified to function as a fuse at apre-determined setting.

The invention has another objective of rechargeability and claims aredirected to use with a recharger and facilities for optimizing recharge.

Another objective is the use of the semiconductor actuator incombination with the invention to control the circulation of electrolytefluid.

A further objective is use of the semiconductor microactuator as afacility for varying the rate of admission of depolarizing fluid to theappliance or cell.

In addition, the objective of better "start-up" power and operation isachieved by mixing an additive oxidizer with the active cathode materialof the cell or cells.

BRIEF DESCRIPTION OF THE DRAWINGS

The features referenced above and other features, objects and purposesof the present invention are discussed in greater detail in associationwith the accompanying drawings which aid in understanding the inventionand its advantages and show a non-exhaustive group of embodiments:

FIG. 1(a) and (b) are schematic presentations of an automaticself-contained semiconductor actuator valve-on-a-chip 1(a ); thevalve-on-a-chip in FIG. 1(b) is particularly modified for thisapplication with an adjusted or special resistor on the chip to carrythe main current or a resistor in parallel with the chip circuitdepending on the application, current requirements and the batteryconfiguration.

FIG. 2 diagrammatically illustrates a miniature metal-air cell with avalve-on-a-chip to control air entry.

FIG. 3 diagrammatically illustrates a larger cylindrical metal-air cellwith a valve-on-a-chip to control air entry.

FIG. 4 diagrammatically illustrates the incorporation of avalve-on-a-chip in or on the battery case to control air access to amultiple cell battery contained in the case.

FIGS. 5 diagrammatically illustrates the contrast between the crosssection of the shunt resistance added to identical FIGS. 5(a) and 1(a)and seen in FIG. 1(b) and the reduced cross-section FIGS. 5(b).

FIG. 6 schematically illustrates the addition of a microprocessor forcontrol purposes in series with an electrical switch.

FIG. 7(a) diagrammatically illustrates a sliding aperture mechanismlinked to a deflecting diaphragm in the closed position and FIG. 7(b)illustrates the same sliding aperture mechanism linked to a deflecteddiaphragm in the open position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1(a) and (b) and FIG. 2 most easily illustrate the principles ofthe invention. The invention is readily adaptable to the family of gasdepolarized electrochemical cells, most of which are described inMcArthur et al., U.S. Pat. No. 4,547,438, Oct. 15, 1985, Zupanic, U.S.Pat. No. 4,529,673, Jul. 16, 1985, Mathews et al., U.S. Pat. No.4,177,327, and in literature cited in those patents.

The term battery, as used in this document, includes an array ofelectrochemical cells, whether connected in series or parallel, or anindividual cell, unless the term cell is employed, in which case, theterm battery used in the same phrase does not include an individualcell.

This invention is useful in a one cell application. This inventionovercomes the power and space deficiencies associated with prior artdevices by using the new combination of an automatic valve made ofdifferent materials and of much smaller size through micromachiningtechniques, preferably a small electronic semiconductor microactuator, a"valve-on-a-chip", after the art of J. H. Jerman, U.S. Pat. No.5,069,419, Dec. 3, 1991, J. H. Jerman, U.S. Pat. No. 5,271,597, Dec. 21,1993, or W. America, U.S. Pat. No. 4,969,938, Nov. 13, 1990, and a"Fluistor" semiconductor microactuator, described in Instruments andApparatus News [IAN], October, 1993, p. 47, and Electronic Design, Nov.1, 1993 p. 34, in conjunction with a sealed fluid depolarizedelectrochemical cell, especially a zinc-air cell. The sole means ofentry of depolarizing fluid is through the valve-on-a-chip.

The class of valves useful in this invention is broader than the Jermanor America art or the "Fluistor" semiconductor microactuator because theself-contained, micromachined valve essential to this invention caninclude modifications of the Jerman or America art. The expression"electrically activated, thermally responsive valve" therefore includesthe Jerman art and like valves that include and importantly contain acantilever deformable element. An alternative design in this class ofelectrically activated, thermally responsive valves is a valve thatcontains juxtaposed members secured at each of their correspondent endswhich members are made of materials of different thermal expansioncoefficients. When one of these elements is heated, preferably themember flexing more rapidly on application of heat, the member bends andopens a gap between the members to admit fluid. Such a design can beachieved by modern micromachining techniques. The term electricallyactivated, thermally responsive valve excludes any valve or actuatorwhich does not contain, at least partially, the deformable element sincethe efficiencies of the invention cannot be obtained absent somecontainment. Containing the deformable element achieves comparableperformance to the Jerman art which has solely transnationaldisplacement of its deformable member as the diaphragm heating varies,which means that the valve-on-a-chip is substantially or completelynon-rotational and has little or no transverse movement in the directionof flow of the depolarizing fluid, which minimizes the space usage.There can be more than two layers and the layers may be of metal orsemiconductor material.

An additional enhancement can be found in the America art which hasgreater pressure characteristics.

This invention also proposes a significant of each of those valves byusing plates of grids, preferably with diamond shaped apertures. The twoplates of grids, when flat against each other, permit no fluid flow, butwhen one (or both) is flexed, the apertures allow much more fluid flowthan a plate or other occlusion device covering an inlet to a valve.

As will be apparent to those skilled in the field, while the art ofJerman and other semiconductor microactuator inventors considersbimetallic construction of aluminum and silicon, other metals such ascopper, silver, gold, zinc, etc. could be substituted for the aluminum.Other semiconductor materials such as carbon, boron, gallium arsenide orindium phosphide are contemplated as substitutions for the silicon inthe invention. These materials can be used in the electricallyactivated, thermally responsive valves referred to herein as well.

The inventions claimed in the America and Jerman art and the "Fluistor"semiconductor microactuator, the microactuators and microvalvesdescribed in the American and Jerman art, and their equivalents made ofdifferent materials are collectively referenced in this invention as asemiconductor microactuator or a valve-on-a-chip.

FIG. 1(a) has a perspective view of a self-contained micromachined,metal-semiconductor bilayer-actuated diaphragm valve described as asemiconductor microactuator after the art of H. Jerman, U.S. Pat. No.5,069,419, Dec. 3, 1991 and as further described in marketing materialsof the assignee of said patent, I.C. Sensors, Inc. which materials areentitled Electrically-Activated, Normally-Closed Diaphragm Valves by J.H. Jerman, the inventor of the valve-on-a-chip. The semiconductormicroactuator pictured in FIG. 1 is approximately 4 millimeters squareand 1 millimeter thick with the diaphragm 2.5 millimeters in diameter.In FIG. 1(a), a micromachined silicon valve body (36) contains a port(37) (normally the outlet port to what will be the interior of thebattery), a valve seat (38), and a port (39) (normally the inlet portfrom the ambient atmosphere outside the battery) with that valve bodymated to another micromachined silicon body (43) with a resistanceheated diaphragm (40), and a metallized area (41) which is theresistance area for heating the diaphragm. An additional resistance, ifone is added, is connected to two valve terminals (44) and (45).

A similar assembly in FIG. 1(b) to that portrayed in FIG. 1(a) has ashunt resistance element (42) added to the chip as shown to make thedevice more functional for situations where the battery current neededfor the apparatus to be powered is greater than could be deliveredthrough the semiconductor microactuator absent a shunt resistor.Alternatively, a thin film resistance element between the terminalscould be added to the chip as shown, physically or by depositingmetallized material on the semiconductor microactuator, to make thedevice more functional in its valve-function-only configuration. Aresistance element of optimized value and power capacity, normallybetween 0.05 and 1 ohms, which resistance is much less than the internalresistance of the semiconductor microactuator, could be wired inparallel with the semiconductor microactuator as an alternative design,especially for larger battery configurations.

The America art may be similarly located in the cell or battery as theJerman art in the prior drawing and the following drawings andvice-versa. The key is that there be a series connection of the valvewith the cell and that the inlet of the valve correspond with the inletof the cell and the outlet of the valve when operating admitdepolarizing fluid into the cell.

As shown in FIG. 2, an exemplary very small gas depolarizedelectrochemical cell, such as for a hearing aid, is comprised of a zincanode mixture (1) disposed adjacent to and in electrical contact with acover (2) (which is shown in FIG. 2 as being round but which can be anyshape and which will be negatively charged in this embodiment), whichzinc anode mixture (1) is one of the electrodes of the cell. A container(11) corresponding in shape to the shape of the cover (2) (which coverwill be positively charged in this embodiment) surrounds a gasket (3)disposed on the inside edge of the container (11), both of whichsurround the cover (2), so that the gasket (3) seals the cell andseparates the negatively polarized cover (2) from the positivelypolarized container (11). Another gasket (4) is disposed on the insidecorner of the container (11) to locally isolate the active cathode (7)from the inside of the container (11) so that electrical output isforced to pass through the series connected semiconductor microactuatorwhich is mounted inside the cavity (10) of the container (11), theactive cathode (7) being a porous cathode layer with a conductive metalmesh or screen in it and being one of the electrodes of the cell. Saidgasket (4) is also disposed on the inside corner of the container tohold adjacent to the active cathode (7) a separator (8) disposed betweenthe zinc anode mixture (1) and the active cathode (7) to prevent thezinc anode mixture from contacting the active cathode, and further tohold adjacent to the active cathode in successive layers beginningadjacent to the active cathode, an electrolyte-proof membrane (5) madeof a material such as Teflon (Dupont Trademark), a porous gas diffusionpad and spacer (6) with a cavity (10) in it in which to place thesemiconductor microactuator, which cavity is aligned with an air inlet(9) (an aperture in the container (11)) so that the entry of air throughthe aperture (9) in the container (11) is controlled by thesemiconductor microactuator, disposed on the inside surface of thecontainer (11) with its inlet (39) over the aperture (9) in thecontainer (11). Electrical contacts are made internal to the cell of thesemiconductor microactuator terminals (44) and (45), with or without ashunt resistance, in series to the active cathode (7) and the exteriorcontainer (11). In order to permit gas communication between theexterior of the cell and the interior, but exclude liquids and solidimpurities, a gas permeable, electrolyte impermeable membrane (5) isdisposed between the porous cathode layer (7) and the porous gasdiffusion pad and spacer (6), which membrane (5) is made of a materialsuch as the product polytetraflouroethylene (such as that sold as Teflon(trademark of Dupont Corporation)). A semiconductor microactuator isdisposed on the inside surface of the container (11) in the earliermentioned cavity in the porous gas diffusion pad and spacer (6) so thatthe sole means of gas communication from the exterior of the battery tothe interior is through the air inlet into and through the semiconductormicroactuator through the gas permeable membrane (5) to the porouscathode layer (7). Electrical connections are made from the terminals(44) and (45) of the semiconductor microactuator to the conductivemember of the cathode layer (7) and to the container (11). A resistance(a thin film resistance is shown as (42)) is attached to the terminalsto be in parallel with the metallized area (1). Although not shown inthe figure, if a lower output of current from the battery is needed, aresistance in series with the semiconductor microactuator may beconnected between the terminals of the semiconductor microactuator andthe container (11).

Additional sealants, cell parts and space refinements may be alsoemployed in such a design without departing from the spirit of theinvention. When the cell is connected to an electrical load, the closingof the circuit containing the load causes current to pass through thesemiconductor microactuator, causing it to open, gas (e.g. air) to beadmitted, and the gas depolarized electrochemical cell to power theapparatus containing the circuit. In other words, the semiconductormicroactuator functions so that when it is closed the interior of thecell is effectively sealed from the ambient, and when it is open, gascommunication from the ambient to the interior of the cell case ispermitted.

The previous embodiment has the semiconductor microactuator connectedbetween the container and the active cathode (7) which is one of theelectrodes of the cell; in the next embodiment, the connection is madebetween the electrode of opposite polarity, the zinc anode mixture, andthe container.

FIG. 3 illustrates another preferred embodiment where the semiconductormicroactuator is disposed in a larger cylindrical cell. The shape couldalso be prismatic. Such a cylindrical cell is comprised of a container(12) which will be negatively charged, which container (12) is round andis shaped like a shallow pan, and has a circumferential edge upturned ata right angle and then bent again at a right angle to form a secondcircumferential edge parallel to and outward from the center of thecontainer. Apertures (16) are penetrated through the first upturnedcircumferential edge. An insulating cap (14) is placed adjacent to andcentered on such container which cap is contained partially by suchupturned circumferential edge. A solid contact member (13) is seated insuch cap. The solid contact member passes through the cell sealstructure to a corrosion resistant conducting collector (25) inelectrical contact with the zinc anode mixture (23). The solid contactmember (13), the corrosion resistant conducting collector (25) and thezinc anode mixture (23) form one electrode of the cell. A semiconductormicroactuator (15) as illustrated in FIG. 1 is disposed in the corner ofsuch container, the semiconductor microactuator being electricallyconnected between the solid contact member of negative polarity (13) andthe container (12). Adjacent to the second outer circumferential edge ofthe container (12) are superposed two insulating Gaskets (18) on top ofand beneath such outer circumferential edge. The Gasket (18) on top ofthe second outer circumferential edge insulates an inside structuralbracing member (17) adjacent to it, which inside structural bracingmember holds the solid contact member (13) in a centered position. Thestructural bracing member (17) has an inlet in it to admit depolarizingGas to the interior of the cell over which inlet is disposed thesemiconductor microactuator between the container (12) and the insidestructural bracing member (1). The semiconductor microactuator is theonly means of air access to the active portion of the cell. On theinside structural bracing member (17), in a direction away from thecontainer (12), is a sealing member (20) which is either porous orcontains vent holes (19) for air entry to the porous cathode member(24). The conducting collector (25) is cylindrical and one end is seatedon and attached to the solid contact member (13). Surrounding theconducting collector (25) is a zinc anode mixture (23) contained withinin a separator member (21) which is shaped like an open ended cylinderwith the open end sealed to the edge of the sealing member (20).Surrounding the separator member (21) is a porous cathode mixture (24)which is electrically conductive, has appropriate catalysts such asmanganese dioxide, and has binders in it. The porous cathode mixture iscontained within a corrosion resistant can (26) made of corrosionresistant metal or other material with conducting properties which canis shaped like an open-ended cylinder. The open end of the can (26) hasa lip bent to the center of its cylindrical shape, which lip is sealedto the gasket (18) beneath the second outer circumferential edge of thecontainer (12) and thus encloses the contents of the cell. A positivecontact piece (27) is superposed over the closed end of the can. Thepositive contact piece (27), the can (26), and the porous cathodemixture are the electrode of the cell with opposite polarity to theelectrode which includes the zinc anode mixture. A decorative label (22)surrounds the outside of the can (26) except on the end where thepositive contact piece (27) covers the can. As in the previousembodiment (FIG. 2), when the semiconductor microactuator is closed, theactive ingredients of the cell are effectively sealed from the ambientand when the semiconductor microactuator is open, gas communication fromthe ambient to the active portions of the cell is permitted.

FIG. 4 shows a third embodiment comprised of an airtight non-polarizedcase (28) surrounding a set of connected cells (29) with apertures (30)on cells (29), having two electrodes in each cell, one of which is apositive pole connection member (32). The cells in this FIG. 4 areconnected in series with intercell connectors (31). A semiconductormicroactuator (33) is disposed inside the surface of the case as over aninlet (35) in the case (28) and electrically connected and disposedbetween at least one negative terminal of the cells (29) and thenegative terminal (34) of the battery assembly. The inlet may have asemipermeable membrane such as Teflon (Trademark of Dupont Co.) placedto prevent non-gaseous material from entering the case (28). The cellsmay be connected in series as shown, or in parallel or some permutationthereof. As in the previous preferred embodiments when the semiconductormicroactuator is in the closed position, the interior of the batterycase is effectively sealed from the ambient, and when the semiconductormicroactuator is in the open position, gas communication from theambient to the interior of the battery case and into the cells ispermitted.

In a plurality of cells such as shown in the drawing, the cells areinternally linked in series, positive to negative pole with the "end"cells having the external electrodes. The group of cells is sealed sothat air can only enter through the vent holes.

There are many examples of gas or liquid depolarized electrochemicalcells in the art, virtually all of which can be adapted, using theexamples above, to use the semiconductor microactuators referenced abovewithout substantially changing the size or power characteristics of thecell. The art of McArthur, Mathews and Zupanic and literature cited inthose patents illustrate the many types of cells to which this inventioncan be adapted.

By inserting a microprocessor chip which has voltage sensing and currentsensing characteristics, and in response to either or both of thosecharacteristics can vary the power supplied to the valve-on-a-chip,particularly to the resistance means in the valve-on-a-chip, furtherrefinements in optimizing or regulating fluid flow can be obtained.

Such a microprocessor chip is optimally placed in the cell adjacent tothe valve-on-a-chip connected by leads to the valve-on-a-chip andcontainer and the conductive member of the cathode layer, or placedinside the airtight non-polarized case near a terminal and thesemiconductor microactuator and can be connected as shown in FIG. 6.

FIG. 6 illustrates a load (51) connected in series with a switch (52),control mechanism (48) and a battery (49). The control mechanism (48)has voltage sensing and current sensing characteristics and can be amicroprocessor chip which responds to voltage and currentcharacteristics. In response to those characteristics, the controlmechanism (48) can vary the power supplied to the valve-on-a-chip,particularly to the resistance in the valve-on-a-chip. By so doing,refinements in optimizing or regulating fluid flow through the actuator(in this case using the valve-on-a-chip) can be used to alter the fluidflow into the battery (49) or alternatively, to another battery. If thebatteries are connected inside an airtight nonpolarized case to aterminal on the exterior of the airtight nonpolarized case, the actuatormay actually be situated on the case and controlled by a mechanism inseries or partial parallel with the battery group inside the case. Thecontrol and actuator mechanism can be used to optimize the load level inbetween subarrays of one cell or multiple cells in a battery as well asoptimize recharging and discharge. The actuator could also be situatedon the appliance and any number of permutations of array and inconjunction with a control circuit utilized.

The functionality of the displacement capability of the semiconductormicroactuators like those of Jerman (IC Sensors) or the "Fluistor" type(Redwood Systems) is improved in gas or liquid depolarized cells orbatteries or other devices by constructing the fluid inlet portion ofthe valve perpendicular to the face of the microactuating part. FIGS.7(a) and 7(b) illustrate the principle. One face part is displacedacross the other to open a plurality of holes rather than only one hole.Thus if the sliding faces are mounted in the side of a battery, abattery case or a battery compartment, much more area for fluid flow anddiffusion would be made available with the small movement of the valveface. Almost any material with adequate engineering properties such asstrength and corrosion resistance could be used for the slide andportion of the valve assembly. Since the displacement force can be veryhigh in these valves, especially the "Fluistor" type, a rather largearea slide assembly could be actuated. Referring to FIG. 7(a), the valveis observed in the closed position with diaphragm 40, metallic strip 41and silicon valve body 43 attached between container part 12 andinternal structural part 17. Valve fixed part 60 is placed and sealed inan opening in container 12 and has ports or ruled openings in its faceas well as guides 64 attached to hold the sliding portion 61 of thevalve which sliding portion has ports or ruled openings 63 offset fromthose of fixed part 60 when the value is closed as shown. In FIG. 7(b)the valve is shown in the open position with diaphragm 42 bowed upwardto accommodate the expansion caused by heating hence lifting theattachment part 46 pulling sliding part 61 up and causing the ports orruled openings 63 to coincide with the ports or ruled openings 63 infixed part 60 thus allowing outside fluid to enter the battery orbattery case or battery compartment depending on the nature of container12.

If it is desired to have the semiconductor microactuator function as afuse then the current carrying capacity of the resistors or the shuntcircuit must be designed to fail at the desired electrical currentlevel. The material chosen for the shunt or resistors will be from amongpossible metals or semiconductor materials such as mentioned above toyield the optimum balance of operating resistance considered against thedesired failure upon overheating caused by the undesired or highercurrent level. The valve body or the shunt could also be insulated toincrease the heating effect so that less current was required to causefailure. Since the resistors driving the bilayer deformation are higherin value, it is anticipated that in most cases the shunt circuit will bethe fuse element intended to fail.

The requirement then would be to make at least a short section of theshunt of the appropriate cross section to "blow" at the desired currentlevel. As shown in FIG. 5(b), in contrast to 5(a) which is identical toFIG. 1(a), the shunt resistance (42) can have a reduced cross-sectionportion (47) to achieve the fuse characteristic.

The semiconductor actuator shown in FIG. 1 will function as a pressurerelief device when pressure is placed on the outlet (37) side againstthe diaphragm.

To design the semiconductor microactuator to function as a vent at apredetermined pressure it is necessary to make the semiconductormicroactuator so that the desired vent pressure equals the sum of thepressure required to overcome the partial pressure of the depolarizingfluid (e.g. oxygen of the air) plus the built-in closure force in thesemiconductor microactuator diaphragm on the area of the valve seat.According to the description of the valve-on-a-chip provided by I.C.Sensors, Inc. (titled Electrically-Activated, Normally-Closed DiaphragmValves by H. Jerman, the inventor of the valve-on-a-chip), thedisplacement in the valve-on-a-chip is fully proportional to the forceapplied without hysteresis. For a valve-on-a-chip with a 5 micronaluminum thickness of the diaphragm and an 8 micron silicon layer, and avalve seat diameter of 400 microns, the most likely opening pressure isthat required to overcome the 3 psi partial pressure of oxygen in theair if the valve-on-a-chip is employed on a metal-air battery. At asacrifice in power required to open it, the valve-on-a-chip can bedesigned to require greater pressure to open. The above reference fromI.C. Sensors, Inc. implies that for the same valve-on-a-chip the springconstant is approximately 160 dynes per micron. Referring to FIG. 1(a)and 1(b), either or both the valve boss (46) and the valve seat (38) canbe made so interference of these parts and deformation of the diaphragm(40) occurs when the valve-on-a-chip is assembled. Then more pressure,i.e., 160 dynes per micron of deformation during assembly, will berequired to open the valve-on-a-chip to relieve the built-in pressure ofthe valve body. The deflection of this particular valve on a chip for a50° C. temperature rise is 27.3 microns. If one assumes that 20 micronsis the maximum deformation which will still permit satisfactoryoperation of the valve-on-a-chip, then the maximum bent pressure beforerelease must overcome the 3200 dynes force (to achieve unloading of thediaphragm (40)), and the effect of the partial pressure of thedepolarizing fluid (3 psi for oxygen in air). Since the area of thevalve opening is only 0.0016 cm², the pressure in the cell must be about3200 dynes/0.1 cm² or 2,000,000 dynes/cm² (29 psi). Thus, the total ventopening pressure would be 32 psi. Any value between three and 32 psicould be achieved by making either or both the valve boss (46) or thevalve seat (38) with more or less height for interference on assembly.Since cells of this type usually are designed with a low vent pressurefor safety reasons, this range covers most designs typically required.

If relief at a different or more specific pressure is desired, the useof an additional layer, or circular web of material on the deformableelement in the semiconductor microactuator or changing the thickness ofthe deformable element will accomplish the fine tuning of the pressurerelief characteristic. Necessarily, the change in the construction ofthe moving or flexing element to accomplish the pressure reliefcharacteristic may necessitate slight relocation or change to theplacement of the heating element so that upon electrothermal actuation,the necessary fluid flow of depolarizing agent to the battery ismaintained.

It is also a useful advantage that if the cell is subjected to a largecurrent overload, the valve function will be destroyed breaking theelectrical circuit if the valve on a chip is in series with the powerdevice, or precluding further admission of oxygen, eventuallyeliminating the power capacity of the cell or cells. Further, leakagefrom malfunction of the cell or battery of cells will damage the openingfunction of the valve-on-a-chip, minimizing damage to the apparatuspowered by the cell or battery of cells. Under such circumstances, thesemiconductor microactuator would act as a safety device.

The valve-on-a-chip can be very small (4 mm.×4 mm.×1 mm.) and thus usesvery little space and can be literally "tucked" into the cell withouthaving to alter the exterior of the cell so radically as to requireredesign of the devices that the fluid depolarized cells typicallyoperate. The preferred embodiment of the invention uses a valve that hassolely transnational displacement of its deformable member as thediaphragm heating varies, which means that the valve-on-a-chip issubstantially or completely irrotational and has little or no transversemovement in the direction of flow of the depolarizing fluid, whichminimizes the space usage. The semiconductor microactuator is aminiature valve literally contained in a device the size of anintegrated circuit "chip". When power is supplied to the semiconductormicroactuator, the semiconductor microactuator opens and allows fluid topass while consuming little power of the cell and with minimal movement.The valve-on-a-chip is available for a variety of operating conditions,namely different flows and different power applications. The artdisclosed below related to adding a resistor or resistance in parallelto the semiconductor actuator valve which gives the valve even broaderuse and more flexibility in this invention.

The dimensions of the valve-on-a-chip are approximately 4 mm×4 mm×1 mm.The thinnest portion of the valve-on-a-chip is perpendicular to thedirection of air flow into the cell. This enables the valve-on-a-chip tobe smallest in the most critical dimension to reduce space consumptionin the cell and to be mounted on the exterior or interior surface of thecell container almost as if a thick paint chip is placed flat on thecell surface.

The principal applications are expected to be for small metal/metaloxide-oxygen depolarized cells but other uses can be readily envisionedand are presented in this invention. For instance, the degree of openingof the semiconductor microactuator could be controlled by a smallcomputer, microprocessor or other means and then the semiconductormicroactuator used as a regulator of reactant air, cooling air,electrolyte circulation or other fluid flows.

In an air/zinc system, each cell delivers about 1.4 volts, in series,two cells deliver 2.8 volts etc. Because this may be above the preferredambient operating voltage of the device being powered, a shunt resistorand the internal resistance of the semiconductor microactuator may bedesigned to slightly reduce the ambient operating voltage delivered bythe cell. If a multiplicity of cells is connected in parallel internallyand the valve-on-a-chip is connected in series with a parallel cellcombination, the cells will deliver the same voltage, but more amperageor current. If the current is above the rated capacity of thesemiconductor microactuator, the semiconductor microactuator must beprotected.

One way to do this is by mounting the semiconductor microactuator on thesurface of the cell inside a battery of cells, connecting thesemiconductor microactuator so that it is in series with a single celladded for the purpose or by inserting a low resistance shunt circuit byor on the chip to divide the current flow between the semiconductormicroactuator and the shunt resistor improving the overall function ofthe invention.

Another way to accomplish this in an array of cells in a battery, withor without a shunt resistor, is to connect the semiconductormicroactuator by one of its terminals to the critical dimension toreduce space consumption in the cell and to be mounted on the exterioror interior surface of the cell container almost as if a thick paintchip is placed flat on the cell surface.

The principal applications are expected to be for small metal/metaloxide-oxygen depolarized cells but other uses can be readily envisionedand are presented in this invention. For instance, the degree of openingof the semiconductor microactuator could be controlled by a smallcomputer, microprocessor or other means and then the semiconductormicroactuator used as a regulator of reactant air, cooling air,electrolyte circulation or other fluid flows.

In an air/zinc system, each cell delivers about 1.4 volts, in series,two cells deliver 2.8 volts etc. Because this may be above the preferredambient operating voltage of the device being powered, a shunt resistorand the internal resistance of the semiconductor microactuator may bedesigned to slightly reduce the ambient operating voltage delivered bythe cell. If a multiplicity of cells is connected in parallel internallyand the valve-on-a-chip is connected in series with a parallel cellcombination, the cells will deliver the same voltage, but more amperageor current. If the current is above the rated capacity of thesemiconductor microactuator, the semiconductor microactuator must beprotected.

One way to do this is by mounting the semiconductor microactuator on thesurface of the cell inside a battery of cells, connecting thesemiconductor microactuator so that it is in series with a single celladded for the purpose or by inserting a low resistance shunt circuit byor on the chip to divide the current flow between the semiconductormicroactuator and the shunt resistor improving the overall function ofthe invention.

Another way to accomplish this in an array of cells in a battery, withor without a shunt resistor, is to connect the semiconductormicroactuator by one of its terminals to the electrode of a single cellas before, but the other semiconductor microactuator terminal would beconnected to the parallel combination of the cells. The semiconductormicroactuator would still be disposed to admit air to all of the cellson the external casing of the Group of cells. More than onesemiconductor microactuator can be disposed and connected for each cell,or subgroup of cells in a battery depending on the use and power beingdelivered.

The embodiments represented herein are only a few of the manyembodiments and modifications that a practitioner reasonably skilled inthe art could make or use. The invention is not limited to theseembodiments. Alternative embodiments and modifications which would stillbe encompassed by the invention may be made by those skilled in the art,particularly in light of the foregoing teachings. Therefore, thefollowing claims are intended to cover any alternative embodiments,modifications or equivalents which may be included within the spirit andscope of the invention as claimed.

What is claimed is:
 1. A fluid depolarized electrochemical batteryhaving at least one cell comprising:at least one semiconductormicroactuator valve means for being the sole means for admittingdepolarizing fluid into said battery, said valve means having a case,two terminals, a closed position, an interior, inlet means for admittingdepolarizing gas to said interior, an outlet from said valve means tosaid battery, slide means for occluding fluid flow disposed to coversaid inlet means, and means for flexing upon application of heat to saidmeans for flexing; said slide means having at least two parallel,juxtaposed grids of apertures and having an open position wherein saidgrids of apertures are aligned to admit depolarizing fluid and a closedposition wherein said grids of apertures are aligned to occlude fluidflow; means for disposing said at least one valve means on said battery;said case having one of said grids of apertures of said slide meansdisposed across and affixed to said inlet means on said case adjacent tosaid interior; electrical resistance means for heating said means forflexing; means for coupling said means for flexing to said other atleast one grid of apertures to admit depolarizing fluid in said openposition; means for electrically connecting said electrical resistancemeans to said two terminals in series with said battery for heating saidelectrical resistance means, so that upon operation of said battery,said electrical resistance means is heated, causing said means forflexing to flex, causing said other at least one grid of apertures toalign with said one of said grids of apertures across said inlet meansin said open position, thus admitting depolarizing fluid into saidbattery.
 2. The fluid depolarized electrochemical battery as in claim 1wherein said at least one valve means acts as a pressure relief valve toallow excess pressure to exit said battery at a predetermined level. 3.The fluid depolarized electrochemical battery as in claim 2 furthercomprising recharging means for connection to said battery forrecharging said battery.
 4. The fluid depolarized electrochemicalbattery as in claim 3 further comprising measurement means and controlmeans responsive to said measurement means for connection to saidbattery for preventing overcharging of said battery.
 5. The fluiddepolarized electrochemical battery as in claim 4 further comprisingmeans for insulating a heating element located inside of said at leastone valve means from said at least one valve means' body in order forsaid heating element to fail if overcurrent flows through said at leastone valve means.
 6. The fluid depolarized electrochemical battery as inclaim 5 further comprising control means having a microprocessor forbeing connected to said battery in order to optimize said battery'sperformance for a given electrical load.
 7. The fluid depolarizedelectrochemical battery as in claim 6 further comprising fluidcirculation means and fluid circulation control means for connection tosaid battery to circulate fluid through said battery.
 8. The fluiddepolarized electrochemical battery as in claim 7 wherein said valvemeans and said actuation means cooperate to cause said battery to ceaseto operate upon leakage of corrosive fluid from said battery to minimizedamage to said electrical device which said battery is powering.
 9. Afluid depolarized electrochemical battery having at least one cellcomprising:at least one semiconductor microactuator valve means, saidvalve means having a closed position, having two terminals, andcontaining means for occluding fluid flow, said means for occludingfluid flow being made of two juxtaposed parallel grids of apertures;means for disposing said at least one valve means on said battery as thesole means for admitting depolarizing fluid into said battery;electrical resistance means on one of said at least two means foroccluding fluid flow; means for electrically connecting said electricalresistance means to said two terminals in series with said at least onebattery for heating said electrical resistance means, so that operationof said battery causes said one of said at least two means for occludingfluid flow to flex so that said grids of apertures are no longerjuxtaposed which unseals said valve means allowing depolarizing fluid tobe admitted into said case through at least one of said grids ofapertures.
 10. A fluid depolarized electrochemical battery according toclaim 9, further comprising:an additional plate juxtaposed parallel tosaid means for occluding fluid flow made of two Juxtaposed parallelgrids of apertures, said means for occluding fluid flow having one saidgrid immediately adjacent to said additional plate; means for connectingsaid additional plate through said one said grid immediately adjacent tosaid additional plate to said grid not adjacent to said additionalplate; said at least one semiconductor microactuator valve meanscontaining a liquid and having electrical resistance means for heatingsaid liquid; means for disposing said liquid within said valve meansadjacent to and sealed by said additional plate for heating by saidelectrical resistance means to cause said liquid to be heated and toexpand upon operation of said apparatus, causing said additional plate,through said means for connecting said additional plate, to flex saidgrid not adjacent to said additional plate so that said grids ofapertures are no longer juxtaposed which unseals said valve meansallowing depolarizing fluid to be admitted into said battery throughsaid at least one of said grids of apertures.
 11. The fluid depolarizedelectrochemical battery as in claim 10 wherein said at least one valvemeans acts as a pressure relief valve to allow excess pressure to exitsaid battery at a predetermined level.
 12. The fluid depolarizedelectrochemical battery as in claim 11 further comprising rechargingmeans for connection to said battery for recharging said battery. 13.The fluid depolarized electrochemical battery as in claim 12 furthercomprising measurement means and control means responsive to saidmeasurement means for connection to said battery for preventingovercharging of said battery.
 14. The fluid depolarized electrochemicalbattery as in claim 13 further comprising means for insulating a heatingelement located inside of said at least one valve means from said atleast one valve means' body in order for said heating element to fail ifovercurrent flows through said at least one valve means.
 15. The fluiddepolarized electrochemical battery as in claim 14 further comprisingcontrol means having a microprocessor for being connected to saidbattery in order to optimize said battery's performance for a givenelectrical load.
 16. The fluid depolarized electrochemical battery as inclaim 15 further comprising fluid circulation means and fluidcirculation control means for connection to said battery to circulatefluid through said battery.
 17. The fluid depolarized electrochemicalbattery as in claim 16 wherein said valve means and said actuation meanscooperate to cause said battery to cease to operate upon leakage ofcorrosive fluid from said battery to minimize damage to said electricaldevice which said battery is powering.
 18. A fluid depolarizedelectrochemical battery comprising:at least two terminals on a sealedcase containing at least one fluid depolarized electrochemical cell withat least one inlet means in said case for funnelling depolarizing fluidinto said at least one cell wherein each of said at least one cell hasat least two electrodes wherein at least one of said at least twoelectrodes is an active cathode; at least one resealable, electricallyactivated and thermally responsive valve means disposed to allow entryof depolarizing fluid into said at least one cell through said inletmeans into said at least one cell's interior only when said battery isoperating to supply energy to an electrical device which said battery isconnected to as a power source, said valve means being comprised ofelectrical resistance means between two terminals to cause a means fordeforming to deform upon application of power to said electricalresistance means, said at least one valve being connected in series toone of said terminals of said battery; and means for actuating said atleast one valve means by closing an electrical circuit which includessaid battery to permit entry of depolarizing fluid to said battery. 19.The battery as in claim 18 wherein said at least one valve means acts asa pressure relief valve to allow excess pressure to exit said cell at apredetermined level.
 20. The battery as in claim 19 further comprisingrecharging means for connection to said battery for recharging saidbattery.
 21. The battery as in claims 20 further comprising measurementmeans and control means responsive to said measurement means forconnection to said battery for preventing overcharging of said battery.22. The battery as in claim 21 further comprising means for insulating aheating element located inside of said at least one valve means fromsaid at least one valve means' body in order for said heating element tofail if overcurrent flows through said at least one valve means.
 23. Thebattery as in claim 22 further comprising control means having amicroprocessor for being connected to said battery in order to optimizesaid battery's performance for a Given electrical load.
 24. The batteryas in claim 23 further comprising fluid circulation means and fluidcirculation control means for connection to said battery to circulatefluid through said battery.
 25. The battery as in claim 24 wherein saidvalve means and said actuation means cooperate to cause said battery tocease to operate upon leakage of corrosive fluid from said battery tominimize damage to said electrical device which said battery ispowering.
 26. A method of regulating fluid flow into a battery having atleast one fluid depolarized electrochemical cell comprising:positioningwithin said battery at least one resealable, micromachined, electricallyactivated and thermally responsive valve means for regulating flow ofdepolarizing fluid into said battery's interior and said cell's interiorthrough inlet means in said battery and said cell, respectively, andthrough said valve means only when said battery is operating to supplyenergy to an electrical device which said battery is connected to as apower source; and electrically connecting said at least one valve meansto an actuator means for sealing said inlet means in said battery toprevent depolarizing fluid from entering said battery and said at leastone cell when said battery is not operating to supply energy to a deviceto which said battery is connected as a power source.
 27. The method asin claim 26, further comprising:applying a pressure to mechanically orelectromechanically open said at least one valve means at apredetermined level.
 28. The method as in claim 27, furthercomprising:connecting a recharging means to said battery for rechargingsaid cell.
 29. The method as in claim 28, further comprising:connectingmeasurement means and control means responsive to said measurement meansto said battery for preventing overcharging of said cell.
 30. The methodas in claim 29, further comprising:connecting shunt resistance means tosaid at least one valve means.
 31. The method as in claim 30, furthercomprising:connecting control means having a microprocessor to saidbattery for optimizing said battery's performance under a givenelectrical load.
 32. The method as in claim 31, furthercomprising:circulating fluid through said battery via fluid circulationmeans and fluid circulation control means.
 33. The method as in claim32, further comprising:disposing an additive oxidizer in said activecathode of said at least one cell of said battery.
 34. The method as inclaim 33, further comprising:disposing means for insulating a heatingelement located inside said at least one valve means from said at leastone valve means' body so that said heating element fails if overcurrentflows through said at least one valve.